Oil space heaters utilizing pot type burners



Oct. 4, 1966 i H. STlERLlN 3,276,508

OIL SPACE HEATERS UTILIZING POT TYPE BURNERS Filed Oct. 5, 1961 5 Sheets-Sheet 1 FIG. 2; T

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0 ll l MMYH HUY //V I/EN TOR J ATTORNEY Oct. 4, 1966 H. STIERLIN OIL SPACE HEATERS UTILIZING POT TYPE BURNERS 5 Sheets-Sheet 2 Filed 001;. 5, 1961 FIG. 3

ATTORNEY IN I/ENTOR HAN ST/ERL IN Oct. 4, 1966 H. STIERLIN 3,275,503

OIL SPACE HEATERS UTILIZING POT TYPE BURNERS Filed Oct. 5, 1961 .3 Sheets-Sheet 5 FIG. 5

FIG. 6 72 72 United States Patent 3,276,508 OIL SPACE HEATERS UTILIZING POT TYPE BURNERS Hans Stierlin, Schlieren, Zurich, Switzerland, assignor to Kuhlapparate G.m.b.H., Schlieren, Zurich, Switzerland Filed Oct. 5, 1961, Ser. No. 143,098 Claims priority, application Switzerland, Oct. 19, 1960, 11,689/ 60 3 Claims. (Cl. 158-37) The instant invention relates to oil space heaters having pot-type burners and fuel oil reservoirs together with fuel dosage mechanisms.

An object of the invention is to provide an open dish oil burner which will overcome the drawback of certain prior art types of such burners in which when too much oil flows into the burner, special expedients must be resorted to in order to remove such excess, for example, by pumping or manually dipping it out.

Another object is to provide a room heater with an open dish oil burner in which the disposition of the main fuel oil reservoir is not limited to below the burner, and in which the need to provide pumps for delivering fuel oil from the main reservoir in sufiicient quantity, up to the maximum heat rating of the heater, is eliminated with any excess in the delivered fuel which is not required for heating (burning) overflowing into an auxiliary reservoir and being returned from there to the main reservoir.

A further object is to provide an open dish oil burner space heater, particularly for positioning in, and heating, rooms of residences, of which the operation is free of smoke and soot at all times including when starting the heater after shut-down as also when extinguishing it.

Still another object is to provide a fully reliable oil space heater of the pot burner type which has at least one auxiliary fuel oil receptacle which can receive the fuel oil flowing back from the pot burner and the feed line when starting and stopping the heating apparatus, which receptacle, at least partially, is below the level of the pot burner, and has an auxiliary conveying means to convey fuel oil back into the main fuel oil reservoir.

Illustrative embodiments of the present invention are shown in FIGURES 1 through 6 which in simplified section show oil burners of pot burner type.

In the illustrative embodiment of my invention shown in FIGURE 1, reservoir 1 may be filled with fuel oil to a level A through a connecting line from a supply, not shown, through an opening in its top normally closed by cover 2, and is provided with a shut-off valve actuatable by knob 3 in the heater fuel feed line 4 supplying oil to the fuel dosage mechanism 5 which is within standpipe 4' and of which float valve 6 automatically controls inlet valve 7. Dosage mechanism within standpipe 4 is operable either manually or by button 8, or automatically by thermostat 9. Float 6 closes valve 7 when the level of fuel oil in standpipe 4', disposed below reservoir 1, into which feed pipe 11 opens, reaches level C. Dosage mechanism 10 connects to burner feed line 11 which opens into the bottom of burner casing 12 and is inclined upwardly from the bottom of standpipe 4. Level C of the fuel oil in standpipe 4' is above the height of the head determined by level B so that the fuel oil can flow by gravity under its own weight without any additional propelling mechanism from standpipe 4 to the lower level B within burner 12 where it is ignitable by electrical plug 21, for example. By means of an additional safety drainage device 17, connected to an intermediate region of burner feed line 11, of which drainage safety device casing or housing 22 is positioned above auxiliary reservoir 30, which in turn is positioned below burner 12, there is provided a safety level D for fuel in the burner feed line by means of overflow ports 23, from which overflowing fuel oil falls into 3,276,508 Patented Oct. 4, 1966 "ice the auxiliary reservoir. Furthermore, safety device housing 22 may be drained of all its fuel automatically by thermostat 19 opening a normally closed drain valve 20 in its bottom, the drained fuel oil splling into auxiliary reservoir 30. Both thermostats 9 and 19 operate in wellknown manner by way of levers to actuate valves in the opening, respectively the closing, direction at predetermined temperatures, as described for example in this applicants prior Patent 3,017,921. It is to be noted that the bottom of safety device 17 is below the bottom of standpipe 4'. In addition, burner feed line 11 is provided with a second draining means 32 in the form of a siphon, operable in the event of any excessive filling of the feed line to produce a fuel oil level F, which is below levels C, D and E, the level E being that at which the lowermost of a plurality of air intake ports 13 of burner 12 is located. Obviously level B is regulated by the flame of the burner; when level B increases, the flame will become larger to such degree that it will consume the increased inflow of fuel oil, ultimately producing a stationary equilibrium condition. If, for any reason, level B of the oil in the .burner lowers, the flame becomes smaller and level B rises, that is, seeks to restore, and ultimately does restore, to the equilibrium condition. To catch all the oil which may drain through opened valve 20 of drainage device 17, as well as any that may be out flowed by siphon 32, and any eventual leakage from other parts of the room heater of my instant invention, catch basin 33 is disposed so as to direct all spilled fuel oil into auxiliary reservoir 30 positioned below burner 12. Auxiliary reservoir 30 is provided with fuel oil pump-conveyor 31 for continuously emptying the reservoir down to a level H, the pumped fuel oil being returned by feedback line 34 to main reservoir 1.

It follows that, in the event of excessive filling of the feed line 11 and hence of the pot burner 12, for example on non-ignition or extinction of the flame, the siphon commences to flow when the fuel oil reaches the level F below levels C, D and E. By its siphoning action, the siphon empties the pot burner and the feed pipe, as also the drainage means 17 down to the level G at which the upper open end of the siphon dips into the fuel oil in the drainage means. Thereupon a new feed of fuel oil may take place until either the room heater operates properly or siphon 32 is again actuated by the rising level of fuel oil. In all figures, like elements are designated by like reference numerals.

The embodiment disclosed in FIG. 2 likewise has an auxiliary fuel oil reservoir 30 and the therewith co-operating auxiliary conveyor 31, as also a feedback line 34. In this embodiment it is possible so to dispose the main fuel oil reservoir 1a that both the fuel oil positioned below and above the pot burner may be fully used, which fact is obviously a very marked advantage for the combination of a favorably positioned and large-volume fuel oil reservoir. As shown in FIG. 2, the desired drainage of fuel oil is by drain valve 20 and by siphon 32a of which one end opens directly from safety device housing 22 in this embodiment. These last mentioned points are of very greate importance in fully automatic, safely operating and fool-proof heating apparatus having electric ignition. Within main reservoir 1a an elevator-conveyor 37 elevates the fuel oil in the main reservoir from level A upwardly to spill it into feed line 38 by which the so elevated fuel flows by gravity into the upper region of safety device casing 22.

In FIG. 3, a basically different embodiment of the instant invention is shown. The main fuel oil reservoir 1b is, however, a lowered reservoir. The catch-basin into which the main fuel oil conveyor 37 pours the fuel oil is simultaneously in the form of an auxiliary reservoir 30', which at the desired time is emptied by control means acting on the auxiliary conveyor 31. The task of the control means is to actuate the auxiliary conveyor means to pump out fuel oil when the heater is shut down, whereas during the normal heating operation thereof, the auxiliary conveyor delivers no oil. This may be accomplished as follows: Stopping the auxiliary conveyor, reversing the drive of the auxiliary conveyor, providing a suction or short-circuiting valve which on normal operation of the heater is closed, respectively open, or similar means. In FIG. 3, a manually or automatically operated tiltable rocker 36 is shown which, during the heating operation, guides the fuel oil transported by auxiliary conveyor 31 back into auxiliary reservoir 30, and only after rocker 36 is tilted into its other position (shown in broken lines) on shutting down the heater, guides the fuel oil transported by auxiliary conveyor 31 back into main reservoir 1b. If, at the same time it be noted that the auxiliary conveyor 31 transports more oil than the dosage buckets of conveyor 37, emptying of both the auxiliary reservoir 30' and of feed line 11 connecting to pot burner 12 may be had, even though the bucket conveyor-elevator 37 continues to operate without change. It will be noted that in this embodiment there is absent the drainage means 17, resulting in a structural simplification and added reliability in operation. However, the siphoning means 32b of which one end extends from a wall of auxiliary reservoir 30 while its other open end is above the interior of main reservoir 1b may readily be employed in this embodiment having main reservoir positioned low.

To use a high and low positioned main reservoir, such as that shown in FIG. 2, without any valves, the use of siphoning means must be avoided, or else the solution shown in FIG. 4, or one similar thereto, must be resorted to. In the embodiment of FIG. 4, use is made of an additional reservoir 40 which is positioned lower than the pot burner, from which reservoir 40 a second conveyor 41, by way of return feed line 34a, transports the oil flowing from siphon 320 having one end extending from a wall of high-walled auxiliary reservoir 30'a within main reservoir 1a and possible leaks, from level I back into the main reservoir. Thereby the object of utilizing a high-low fuel oil reservoir with a siphoning emptying means and drainage of the feed line to the burner without using a drain valve is effected.

It will be noted that in FIG. 4, the first auxiliary reservoir 30' being disposed within the main fuel oil reservoir 1a, elevation of the walls of the auxiliary reservoir to above the uppermost reservoir is required, level A, but this nevertheless has spatial and fuel oil transport advantages. Obviously, the second auxiliary reservoir may also be within main reservoir 1a. Such reservoir arrangement is of particular importance when all the fuel oil conveyors are driven from a common shaft, especially if all the conveyors are in the form of bucket conveyorelevators which, with appropriate design, require no lower guide wheel.

In FIG. 5, a further variant embodiment is disclosed in which the emptying of the feed lines is neither by a valve nor by an auxiliary conveyor but by a continuously open drain or weep aperture 45 through which, upon interruption and cessation of fuel oil feed to a catch basin means 47 and to feed pipe 11, for example by stopping or reversing the main conveyor 37, or by tipping a rocker in the opposite direction, automatic emptying of burner 12, feed line 11 and basin means 47, takes placing. Correct dosages of fuel oil are furnished to burner 12 during the heating period in such manner that while the conveyor means transports exactly measured volumes of fuel oil, such volumes are in excess of those required for heating. The division of such excessive quantity of fuel oil is obtained by properly dimensioning outflow apertures 45 and 46 of basin means 47 so that the required volume of fuel oil flows through aperture 46 and feed line 11 into burner 12, the remainder flowing through weep aperture 45. Within basin means 47 receiving fuel oil from main reservoir 10, which in this embodiment is positioned within auxiliary reservoir 30'b, from the fuel oil conveyor 37 there is established a level K which is above level B in the pot burner, level K being the regulating level in this embodiment as is level C of my FIGURE 1 structure. Level K is maintained at a predetermined height neither by a regulating float nor by an overflow means. But rather such level is established of itself at a height dependent on the conveyed quantity of fuel oil and the dimensions of the restrictive apertures 45 and 46 to obtain a balance between the inflowing and outflowing amounts of fuel oil. For example, with increased viscosity of the fuel oil, as a result of temperature and/or quality variations in the fuel oil, level K will be higher notwithstanding that the same volume of fuel oil is delivered to basin 47 until, because of the increased outflow head, balance and equilibrium is again restored between inflow and outflow. Nevertheless, the volumetric division of the fuel oil between burner 12 and outflow aperture 45 will practically be unaffected thereby, since the choking effect of the restrictive apertures 45 and 46 has not changed. It must here be noted that soiling of the restrictive apertures may be prevented by using filters, and that if filters are not used the above mentioned division of the fuel oil may be altered. Overflow standpipe 48 is for fixing safety level D, and the siphon drainage means 32d, of which one arm extends from a downward extension of catchbasin 47, into which basin extension the fuel oil outflowing from catch basin means 47 through aperture 46 flows directly, while the other arm of the siphon is positioned to empty the overflowing fuel oil into auxiliary reservoir 30'b, being positioned beyond aperture 46 directly in the feed line .as shown. This embodiment likewise includes a high-low reservoir arrangement and uses an auxiliary container 30b below the pot burner as also an auxiliary conveyor 31a for continuously emptying fuel oil from the auxiliary reservoir, fuel oil continuously flowing thereinto during operation of the heater through the open weep aperture 45, back into the main reservoir 1c.

A further and preferred embodiment is shown in FIG. 6 in which the auxiliary reservoir 30'c with its auxiliary conveyor 31a is disposed within the main fuel oil reservoir 1c, the auxiliary reservoir being at a level below pot burner 12, and in which the main and auxiliary conveyors, 37 and 31a, are both bucket conveyor-elevators and are driven by a common shaft 50. An outlet means 60 at the top of main reservoir 1c guides fuel oil transported by main conveyor-elevator 37 to feed line 11. The advantage of this arrangement resides in the drainability of both pot burner 12 and feed line 11 by valve drainage means 17a as also in the freedom of selection of both the location and position of the main reservoir. In this embodiment, the utilization of additional drainage means, in the form of siphon 32e, is made possible with an auxiliary reservoir positioned lower, as is auxiliary reservoir 30'c in this embodiment, than pot burner 12 mounting ignition plug 21. Siphon 32e is so connected to feed line 11, and hence to pot burner 12, at a position below air inlet ports 13 of the burner that (a) on excessive filling of the line and burner with fuel oil, or (b) non-ignition of the fuel oil in the burner, or (c) extinction of the flame, the siphon commences to flow when the fuel oil reaches a predetermined level F below level E. By its siphoning action, the siphon empties the pot burner and the feed line, as also drainage means 17a, down to level G at which the upper of the ends of the siphon again dips into fuel oil in the standpipe housing of valve-safety means 17a. Thereupon new feeding of fuel oil occurs and continues either as long as the heater operates properly or siphon 32a is again actuated by a rising level of the fuel oil. A portion of the fuel oil elevated by main conveyor-elevator in the main reservoir flows by vvay of downwardly inclined outlet means 60, positioned at the upper region of main reservoir 1c, into the top region of stand-pipe 70 located within auxiliary reservoir 30'c, the height of standpipe 70 being less than that of the auxiliary reservoir; the remainder of the so transported fuel oil spilling into main reservoir 10. The main drainage means, normally closed valve 17a, is located at the bottom of standpipe 70 which, in turn, is above the bottom of auxiliary reservoir 300. Fuel oil transported by auxiliary elevator-conveyor 31a empties (a) a portion thereof by way of downwardly inclined outlet means 34 at the upper region of the auxiliary reservoir into main reservoir and (b) the remaining fuel oil into the auxiliary reservoir. One end of siphon 32 opens into standpipe '70 at substantially the level G at which feed line 11 connects with the lower region of standpipe 70, while the other end of the siphon is positioned above the normal level of fuel oil in the auxiliary reservoir. Furthermore, the oil oven is provided with a ventilator 51 for supplying and transmitting sufficient air for combustion S2 and circulating heated air 53 about the heater. The drive for shaft 50 of the bucket conveyorelevators is from the same drive shaft 54 as the drive of ventilator 51, although appropriately stepped down. The stepping down is conveniently by synthetic ropes 55 over plain pulley discs 56. This type of drive thus requires but a single motor 57 for all drives. The space heater is jacketed by a casing '71 having a plurality of openings 72 to the ambient air and connecting with duct means 52 and 53.

The above described illustrative embodiments demonstrate the advantage of oil space heaters according to the invention in which it is possible to dispose the main fuel oil reservoir in any desired position and at any desired region of the assembly. In addition, the shape of the reservoir is freely selectable, which fact is of major importance on the matter of spatial economy. Furthermore, the inventive embodiments, with the complete freedom of their disposition, permit of the ready emptying of the fuel oil feed system to the burner, which is an absolute necessity in starting and stopping the burner. Furthermore, in these new configurations of oil burners, the use of a drain valve for causing a return flow of fuel oil from the hot zone of the oven is not required, so that this element, a source of repeated and relatively frequent disturbance in the operation of oil space or room heaters, is avoided, and simpler and safer operative solutions by the use of auxiliary fuel oil conveyors are made possible. All such changes from what was prior known contribute marketdly and significantly to increasing the dependability in operation of the oil heaters of this invention, it being noted that the stabilized level B of fuel oil in the embodiments of FIGURES 2, 3, 4, 5 and 6, is maintained by the fiame itself as above described for the embodiment of FIG- URE 1.

What I claim is:

1. An oil space heater comprising a pot burner,

means in the burner for igniting fuel oil supplied to the burner,

a fuel oil main reservoir,

an auxiliary fuel oil reservoir positioned within the main reservoir,

a first measuring conveyor-elevator within the main reservoir,

a first outlet means at the top region of the main reservoir for receiving fuel conveyed by the first conveyorelevator,

a second conveyor-elevator within the auxiliary reservoir, the transportation capacity of the second conveyor-elevator being in excess of that of the first conveyor-elevator,

a second fuel outlet means at the top of the auxiliary reservoir;

a standpipe within the auxiliary reservoir, the first fuel outlet means opening into the standpipe, the second fuel outlet means opening into the main reservoir, each outlet means being inclined to cause fuel within the outlet means to flow therefrom by gravity,

a fuel feed arrangement from a lower region of the standpipe to the burner,

first drainage means connected to the standpipe for normally maintaining the level of fuel oil in the standpipe, the burner and the feed arrangement at a predetermined level below the fuel ignition means and for spilling any excess fuel therein back into the auxiliary reservoir, and

second drainage means connected to the standpipe which are closed during operation of the burner and opened on extinction of the burner instantaneously by gravity to drain all fuel oil from the burner, the feed arrangement and the standpipe back into the auxiliary reservoir.

2. The oil heater according to claim 1 in which a drive shaft is common to both conveyonelevators,

a jacketing casing about the oven and having a plurality of air inlets,

a ventilator blower fan,

duct means having a plurality of outlets connecting the blower fan to the jacketing casing for supplying air thereto, and

an electric motor driving the drive shaft and the blower fan.

3. A fuel oil space heater comprising a fuel oil main reservoir,

a pot burner,

a fuel oil feed system between the main reservoir and the pot burner,

a fuel oil level limiting means,

a fuel oil drainage means,

at least one auxiliary fuel oil reservoir of which at least a portion is below the level of the burner and so positioned that (a) on a starting operation failing to ignite the fuel oil in the burner and the adjacent region of the feed system said fuel oil will backfiow by gravity through the level limiting means into the auxiliary reservoir, and (b) on stopping the heater the fuel oil in the burner and the adjacent region of the feed system will backfiow through the drainage means into the auxiliary reservoir, and

motor-driven fuel oil conveying means for returning backflowed fuel oil from the auxiliary reservoir to the main reservoir.

References Cited by the Examiner UNITED STATES PATENTS 1,043,488 11/1912 Waugh 15837 1,862,910 6/1932 Schutz 15873 X 2,188,801 1/1940 Worth 184-61 2,481,491 9/1949 Bishop 15849 X 2,592,132 4/1952 Feilden et a1. 15836 2,828,761 4/1958 Weibert 137132 3,017,921 1/1962 Stierlin 15836 X FOREIGN PATENTS 518,425 2/1931 Germany.

FREDERICK L. MATTESON, In, Primary Examiner.

MEYER PERLIN, Examiner.

R. A. DUA, Assistant Examiner. 

1. AN OIL SPACE HEATER COMPRISING A POT BURNER, MEANS IN THE BURNER FOR IGNITING FUEL OIL SUPPLIED TO THE BURNER, A FUEL OIL MAIN RESERVOIR, AN AUXILIARY FUEL OIL RESERVOIR POSITIONED WITHIN THE MAIN RESERVOIR, A FIRST MEASURING CONVEYOR-ELEVATOR WITHIN THE MAIN RESERVOIR, A FIRST OUTLET MEANS AT THE TOP REGION OF THE MAIN RESERVOIR FOR RECEIVING FUEL CONVEYED BY THE FIRST CONVEYORELEVATOR, A SECOND CONVEYOR-ELEVATOR WITHIN THE AUXILIARY RESERVOIR, THE TRANSPORTATION CAPACITY OF THE SECOND CONVEYOR-ELEVATOR BEING IN EXCESS OF THAT OF THE FIRST CONVEYOR-ELEVATOR, A SECOND FUEL OUTLET MEANS AT THE TOP OF THE AUXILIARY RESERVOIR; A STANDPIPE WITHIN THE AUXILIARY RESERVOIR, THE FIRST FUEL OUTLET MEANS OPENING INTO THE STANDPIPE, THE SECOND FUEL OUTLET MEANS OPENING INTO THE MAIN RESERVIOR, EACH OUTLET MEANS BEING INCLINED TO CAUSE FUEL WITHIN THE OUTLET MEANS TO FLOW THEREFROM BY GRAVITY, A FUEL FEED ARRANGEMENT FROM A LOWER REGION OF THE STANDPIPE TO THE BURNER, FIRST DRAINAGE MEANS CONNECTED TO THE STANDPIPE FOR NORMALLY MAINTAINING THE LEVEL OF FUEL OIL IN THE STANDPIPE, THE BURNER AND THE FEED ARRANGEMENT AT A PREDETERMINED LEVEL BELOW THE FUEL IGNITION MEANS AND FOR SPILLING ANY EXCESS FUEL THEREIN BACK INTO THE AUXILIARY RESERVOIR, AND SECOND DRAINAGE MEANS CONNECTED TO THE STANDPIPE WHICH ARE CLOSED DURING OPERATION OF THE BURNER AND OPENED ON EXTINCTION OF THE BURNER INSTANTANEOUSLY BY GRAVITY TO DRAIN ALL FUEL OIL FROM THE BURNER, THE FEED ARRANGEMENT AND THE STANDPIPE BACK INTO THE AUXILIARY RESERVOIR. 